The purpose of the current study is to continue to optimize conditioning regimens in high-risk patients with severe aplastic anemia transplanted with marrow from HLA-compatible unrelated donors. Specifically, the study will determine whether the addition of fludarabine to the conditioning regimen previously described by Deeg et al. will permit a reduction in the CY dose, to a point where sustained hematopoietic engraftment and survival are maintained (or improved), while the frequency of major regimen-related toxicity (RRT) and early deaths is reduced.

DFS includes graft failure, regimen-related toxicity (RRT), and early death. Graft Failure is defined by lack of neutrophil engraftment (ANC less than 0.5 x 10^9/L for 3 consecutive days on different days). Major RRT is defined as severity of grade 4 in any organ system or grade 3 for pulmonary, cardiac, renal, oral mucosal or hepatic. Early death is defined as death prior to Day 100 post-transplant.

Primary and secondary graft failure are included, secondary graft failure is defined by initial neutrophil engraftment followed by subsequent decline in the ANC to less than 0.5 x 10^9/L for three consecutive measurements on different days, unresponsive to growth factor.

Patients up to 65 years of age at time of registration with a diagnosis of SAA; SAA is defined as follows:

Bone marrow cellularity less than 25% or marrow cellularity less than 50% but with less than 30% residual hematopoietic cells

Two out of three of the following (in peripheral blood): neutrophils less than 0.5 x 10^9/L; platelets less than 20 x 10^9/L; reticulocytes less than 20 x 10^9/L

Patient must have an available unrelated donor with a 7/8 or 8/8 match for HLA-A, B, C, and DRB1 antigen; typing is by DNA techniques: intermediate resolution for A, B, and C, and high resolution for DRB1; HLA-DQ typing is recommended but will not count in the match

Patient and/or legal guardian able to provide signed informed consent

Matched unrelated donor must consent to provide a marrow allograft

Patients with adequate organ function as measured by:

Cardiac: left ventricular ejection fraction at rest must be greater than 40% or shortening fraction greater than 20%

Hepatic: serum bilirubin less than 2x upper limit of normal for age as per local laboratory) (with the exception of isolated hyperbilirubinemia due to Gilbert's syndrome), alanine transaminase (ALT) and aspartate transaminase (AST) less than 4x upper limit of normal for age (as per local laboratory)

Renal: serum creatinine less than 2x upper limit of normal for age (as per local laboratory)

Presence of large accumulation of ascites or pleural effusions, which would be a contraindication to the administration of methotrexate for GVHD prophylaxis

Known severe or life-threatening allergy or intolerance to ATG or cyclosporine/ tacrolimus

Planned administration of alemtuzumab (Campath-1H) or other investigational agents as alternative agent for GVHD prophylaxis

Concomitant enrollment in a Phase I study

Positive patient anti-donor lymphocyte crossmatch in HLA-A or B mismatched transplants; the definition of match is in Section 2.2.1; the crossmatch would only apply to mismatches at HLA-A or B, not DRB1 or HLA-C

Prior allogeneic marrow or stem cell transplantation

Patients with prior malignancies except resected basal cell carcinoma or treated carcinoma in-situ; cancer treated with curative intent less than 5 years previously will not be allowed unless approved by the Medical Monitor or Protocol Chair; cancer treated with curative intent more than 5 years previously will be allowed

Contacts and Locations

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To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00326417